Rolling up a list of 2 separate picklist fields, into 1 singular string from the same child

[simoneduckworth]

I might be pushing the boundaries here of what rollup can do, and so far I've not managed to make it work (yet!)

I have a Long text area field on Account, and I'm looking to roll up all of the active contracts values between 2 picklist fields, Core Service and Service Type (both custom picklist fields located on the Contract).

In an ideal world, I would want to couple up the Contracts values so I'd end up with a list in the respective Account field such as Core Service 1, Service Type 1;Core Service 2, Service Type 2;Core Service 3, Service Type 3

Firstly, I set up the rollup in a triggered flow, where I appreciate that I can only add one option into the "Rollup Object Lookup Field"

I did try to explore whether the "Groups By Fields" would try and compile the full string - primarily, we can't use the Service Type in a separate field, given there's tight coupling with the Core Service, which is why I'm looking to combine them into one text string.

I'm just exploring if I'm out of my mind and pushing the boundaries here, or if it is something that's technically feasible but I've gone about it the wrong way. The component doesn't actually fail, but no text output is actually returned when testing it in our environment. It may just be that I need to run a get and loop through the values manually to compile it, but thought I'd explore it first with rollup!

[jamessimone]

If you're looking to concatenate the values from each picklist into a single field, you can do that by linking two Rollup Custom Metadata records together using a Rollup Grouping parent record. So you'd set up a CONCAT rollup for each field pointing to the same parent field, and link the two together by setting the rollup grouping lookup on each CMDT record.