What is the evidence that someone is filled with the Holy Spirit?

From a catholic tradition perspective, there is no immediate or one criteria. "Know them by their fruits", as far as I know, is the only criteria.

Unfortunately, this depends on what you consider good fruit :) So while I will tell you, that a person calling for you to separate from the catholic church is clearly a negative sign, to someone else, may be a good sign :)

There can be different manifestations.

Intelligence, knowledge and wisdom:

• and I have filled him with the Spirit of God, with ability and intelligence, with knowledge and all craftsmanship, (Exodus 31:3 ESV)
• and he has filled him with the Spirit of God, with skill, with intelligence, with knowledge, and with all craftsmanship, (Exodus 35:31 ESV)
• Now Joshua son of Nun was filled with the spirit of wisdom because Moses had laid his hands on him. So the Israelites listened to him and did what the Lord had commanded Moses. (Deuteronomy 34:9 ESV)

Power, boldness and authority:

• But as for me, I am filled with power, with the Spirit of the Lord, and with justice and might, to declare to Jacob his transgression, to Israel his sin. (Micah 3:8 ESV)
• But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.” (Acts 1:8 ESV)
• Then Peter, filled with the Holy Spirit, said to them, “Rulers of the people and elders, (Acts 4:8 ESV)
• And when they had prayed, the place in which they were gathered together was shaken, and they were all filled with the Holy Spirit and continued to speak the word of God with boldness. (Acts 4:31 ESV)
• 9 But Saul, who was also called Paul, filled with the Holy Spirit, looked intently at him 10 and said, “You son of the devil, you enemy of all righteousness, full of all deceit and villainy, will you not stop making crooked the straight paths of the Lord? 11 And now, behold, the hand of the Lord is upon you, and you will be blind and unable to see the sun for a time.” Immediately mist and darkness fell upon him, and he went about seeking people to lead him by the hand. (Acts 13:9-11 ESV)

Joyful utterances:

• 41 And when Elizabeth heard the greeting of Mary, the baby leaped in her womb. And Elizabeth was filled with the Holy Spirit, 42 and she exclaimed with a loud cry, “Blessed are you among women, and blessed is the fruit of your womb! 43 And why is this granted to me that the mother of my Lord should come to me? 44 For behold, when the sound of your greeting came to my ears, the baby in my womb leaped for joy. 45 And blessed is she who believed that there would be a fulfillment of what was spoken to her from the Lord.” (Luke 1:41-45 ESV)
• 18 And do not get drunk with wine, for that is debauchery, but be filled with the Spirit, 19 addressing one another in psalms and hymns and spiritual songs, singing and making melody to the Lord with your heart, 20 giving thanks always and for everything to God the Father in the name of our Lord Jesus Christ, (Ephesians 5:18-20 ESV)
• What am I to do? I will pray with my spirit, but I will pray with my mind also; I will sing praise with my spirit, but I will sing with my mind also. (1 Corinthians 14:15 ESV)

Prophecy, dreams & visions:

• 17 “‘And in the last days it shall be, God declares, that I will pour out my Spirit on all flesh, and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams; 18 even on my male servants and female servants in those days I will pour out my Spirit, and they shall prophesy. (Acts 2:17-18 ESV)
• But he, full of the Holy Spirit, gazed into heaven and saw the glory of God, and Jesus standing at the right hand of God. (Acts 7:55 ESV)
• And his father Zechariah was filled with the Holy Spirit and prophesied, saying, (Luke 1:67 ESV)
• Pursue love, and earnestly desire the spiritual gifts, especially that you may prophesy. (1 Corinthians 14:1 ESV)

Tongues:

• And they were all filled with the Holy Spirit and began to speak in other tongues as the Spirit gave them utterance. (Acts 2:4 ESV)
• 44 While Peter was still saying these things, the Holy Spirit fell on all who heard the word. 45 And the believers from among the circumcised who had come with Peter were amazed, because the gift of the Holy Spirit was poured out even on the Gentiles. 46 For they were hearing them speaking in tongues and extolling God. (Acts 10:44-45 ESV)

The fruit of the Spirit:

• 22 But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, 23 gentleness, self-control; against such things there is no law. 24 And those who belong to Christ Jesus have crucified the flesh with its passions and desires. (Galatians 5:22-24 ESV)

Various traditions have different answers on this. There's no consensus. (That may be your answer. The rest may be irrelevant.)

Greg Bala has already addressed the Catholic view. Here are some Protestant ones, ranging from extreme Pentecostal to conservative Christian. None of these are universal. Some groups believe some of them, others think that some of the beliefs are insane, pure guff, or just wrong. I'm not saying which is which, just listing them out.

• Ability to pick up deadly serpents, not get bitten, and be immune to their poison if they do bit you

• Being overtaken with Holy Laughter

• Prophecy
• Growling, dancing, shaking, barking like dogs, and even some even being stuck in positions of paralysis.
• Speaking in tongues

On the less Charismatic end of the spectrum...

• Possessing the fruits of the Spirit - a combination of Matthew 7:16 and Galatians 5:16-25. Many non-Charismatic protestants see these fruits as evidences that we are filled with the Spirit.

Matthew 7:16 (KJV) Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?

Galatians 5:16-25 (KJV) 16This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. 17For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. 18But if ye be led of the Spirit, ye are not under the law. 19Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, 20Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, 21Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God. 22But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, 23Meekness, temperance: against such there is no law. 24And they that are Christ's have crucified the flesh with the affections and lusts.

25If we live in the Spirit, let us also walk in the Spirit. 26Let us not be desirous of vain glory, provoking one another, envying one another.

This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. But if ye be led of the Spirit, ye are not under the law. Now the works of the flesh are manifest, which are these; Adultery, fornication, uncleanness, lasciviousness, Idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, Envyings, murders, drunkenness, revellings, and such like: of the which I tell you before, as I have also told you in time past, that they which do such things shall not inherit the kingdom of God. But the fruit of the Spirit is love, joy, peace, longsuffering, gentleness, goodness, faith, Meekness, temperance: against such there is no law. And they that are Christ's have crucified the flesh with the affections and lusts. If we live in the Spirit, let us also walk in the Spirit. Let us not be desirous of vain glory, provoking one another, envying one another. - Galatians 5:16-26

As easy as it is to focus on the various lists provided in Scripture, the baseline of what Paul lays out in this passage is a process. Those that are Christ's have crucified fleshly affection and lust when they united with Him in his death...the power of sin is broken. They have new life when they are united with Him in his resurrection...the Holy Spirit lives within them and the battle begins. If there is struggle with and progress against sin then the Holy Spirit is present.

We also have a responsibility to "walk out what has been worked in":

According as his divine power hath given unto us all things that pertain unto life and godliness, through the knowledge of him that hath called us to glory and virtue:  Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust. And beside this, giving all diligence, add to your faith virtue; and to virtue knowledge; And to knowledge temperance; and to temperance patience; and to patience godliness; And to godliness brotherly kindness; and to brotherly kindness charity. For if these things be in you, and abound, they make you that ye shall neither be barren nor unfruitful in the knowledge of our Lord Jesus Christ. But he that lacketh these things is blind, and cannot see afar off, and hath forgotten that he was purged from his old sins. - 2 Peter 1:3-9

Paul also says that the paradigm through which we judge ourselves and others has shifted. Even though we once judged Christ, ourselves, and others according to the flesh, according to worldly wisdom, we should no longer judge in this fashion:

For the love of Christ constraineth us; because we thus judge, that if one died for all, then were all dead: And that he died for all, that they which live should not henceforth live unto themselves, but unto him which died for them, and rose again. Wherefore henceforth know we no man after the flesh: yea, though we have known Christ after the flesh, yet now henceforth know we him no more. Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new. - 2 Corinthians 5:14-17

Do you know someone who confesses that Jesus Christ is the Son of the living God and who, regardless of how difficult or fruitless their struggle with sin appears to be, continuously clings to the crucified and risen Lord as the only hope? Encourage such a one, judging that, according to the promises of God and not according to the flesh, this is a new creation. Flesh will fail but the promises of God are sure.