Search and filter by using several keywords in one cell (google sheet)

Hi

I have an app that filter through a google sheet and display the rows containing one keyword that mach the searchterm.

I now would like to add several keywords in the same cell and have thunkable search through all. I need to do some filtering by the “,” but I do not know how.

Also. Where do I add the “lowercase” object to make it case sensitive.
And last “problem” to solve. Make the result to show everything containing the string text written in the search field. If the user write car, it will show carshow, carproblems, carvideos (not that I have car in my sheet but just as an example)

I would consider creating a formula in the Google Sheet to do all of that and then access the results from Thunkable. That also allows you to use AI to generate a complex formula.