You currently have:
Modify it to be:
Where ProjectTasks|Client is a new Tutorial: What are Table Occurrences? of ProjectTasks linked in like this:
HoursLogged::fkClientsID = ProjectTasks|Client::fkClientsID
Then your Conditional value list can be defined to list Project IDs from ProjectTasks|Client, Include only related values starting from HoursLogged.
PhilModJunk, you are amazing! Thank you so much. Worked perfectly.