Concatenate a string of text from one col., from corresponding text in another col. that matches a cell

[Lisa116]

The goal is to have a concatenated list separated by commas, based on a different list that matches a certain cell. All of which are text.

sheet 1 contains two lists; (I need to keep these lists whole)
first list has individual items (which will be concatenated)
second list which is different and can contain multiple of the same items (this list will match the cell on sheet 2).

sheet 2 will contain the concatenated list in one cell and the match reference in another cell.

I tried using index match but I only get the first matched cell and not the rest of the list.

Thank you,
Lisa

 

[Peter_SSs]

Is TEXTJOIN available in all of the newer versions of Excel? I thought it was only available in the Excel 365 subscription.

Suppose it depends on the definition of 'newer'. Help page lists:
Excel for Office 365, Excel for Office 365 for Mac, Excel Online, Excel 2019, Excel 2019 for Mac, Excel for iPad, Excel for iPhone, Excel for Android tablets, Excel for Android phones, Excel Mobile