Code/formula to extract data from one cell that has multiple selections

Hi all

Looking for help on this if anyone has any ideas

The first sheet called functional requirements produces reference numbers in column B, and in column L they can select rules that are linked to that requirement. I have code that enables them to select more than one rule so the drop down box adds all the selections they chose.

The second sheet is a list of the rules. Column B is the rule number and is the data validation for column L on the first sheet.

What I want to do in the second sheet is use column D to list all the requirements that have the rule (in column B of second sheet), listed in Column L on the first sheet.

Hope that makes sense! I have tried numerous ways but only got as far as extracting a table with the first column being the project and then the rest of the row listing the rules selected, but again, hit a dead end

If you know of the best way forward it world really help

Thanks in Advance