How can I generate a list of all "On Hold" club members?

To identify your members currently On Hold, we would recommend generating a a club export.

Go to Club > Memberships
To the top-right of the table, click Actions > Export.
Export your whole list.
There will be a "Status" column in the spreadsheet export to identify which memberships are currently on hold.

To find the exact Hold Dates, you will need to go into the club membership and it's recorded under Hold Dates.