With the idexx integration I pretty much dont use the other investigations.  but I just realized I need to update my QML form

This doesnt seem to work...despite I know that the document gets provided with an act.patientInvestigation

Clinic ID: [investigation:accountId()]

This and retrieving a set of associated product names / identities (which is where we have stored the associated codes for each test historically before tests were a thing.

I tried using [list:names(openvpms:get(., 'products'))] 

given that the act has a products participations node I assumed that would work but that gave me

Cannot invoke public java.lang.String org.openvpms.archetype.function.list.ListFunctions.names(java.lang.Object); Invalid property name: name

Also tried 

[list:values(openvpms:get(., 'products'),'identities')]

which was a wild guess.