This procedure allows you to put a video clip inside of words, and have that on top of your main video. This can help keep the audience’s attention, and allow words to be fun and energetic instead of monotonousness.
The first step is having your background video and the video you want to play inside of the words ready.
The next step is to go File, and then down to New Title.
Then click the text tool and type the words you would like to use, and change your font family to preferably to a more bubble letter scheme.
Then bring your title selection down to the timeline and make it higher than the main video, like video 3.
After that on your main video click visual effects and choose keying and then drag over track matte key. And then on the main video under effect controls change matte to video 3.
Now you will drag your background video over to the timeline and make it video1.
Then go back into the effects and under perspective click on bevel alpha.