Multi Names Separated by Comma based on another cell with comma delimited data

Hello,

I am trying to find a formula to auto populate trainer names based on 2 different columns. I can get this with a filter formula however one of my columns has several classes listed separated by a comma and I want all trainers to be listed separated by comma for the classes listed in the other column. I have attached a spreadsheet to show what I am trying to accomplish. Please let me know if there are any questions.

Thank you,
Tim