Interaction diagram modelling

Hi, Being a large company with multiple internal and external parties doing the same, we would like to complement our generic processes with interaction diagrams detailing who talks to whom in a given context.
What would you suggest in terms of model and framework to model these interactions? To make it tangible, let’s take two operational support organizations with their respective 1st, 2nd and 3rd line support, which could have 1L<>1L bis interactions, or in some case 1L <> 2L bis interactions. How would you ensure candid users could retrieve pertinent information for their own context (i.e: Being a 2L who are my 3L?), and similarly how could they backtrack certain information (i.e: Being a 1L who could contact me for support?).
On top of it we would like to add the notion of which relationship is applicable in which context or under which condition (i.e: 1L could reach out to 3L if the faulty system is X) So far we have modelled it in two ways, a gigantic and hard to read Archimate diagram (business actor>application component>business actor>application component>…), and a split view of the same which unfortunately sacrifices the overall picture in favor of readability.
Note also while the above example seems easy to model, in practice we speak about hundreds of parties interacting with each other, and sometimes deviating from common sense in terms of 1L>2L>3L communication chain.
Thanks for your suggestions.