How to replicate a session scope in GA4 for a custom dimension?

Question

I have a critical requirement in a GA4 migration in which I need to be able to run a report that displays my custom dimension and in how many sessions it was used. E.g:

customDim	Sessions (10)
123	3
5555	3
9999	4

The problem is that in unviersal analytics the customDim is set as session scope, and currently in GA4 session scope doesn't exist, so my customDim counts are greater than the total number of sessions since it's treated as an event scope.

Any tips on how I could try to mimic a session scope in GA4? One idea I had was to just capture my customDim once per session and send the value only once, but that hasn't worked so far.

Answer 1

Your idea should work. Just set up your custom dimension (event property) as hit-level in GA4, then when you send it, you make a 30-minute cookie, which, if exists, should block it from being sent. GTM would do the trick.