Paladin 3 (Oath of Conquest) / Cleric 1 (Forge Domain)
Source: Xanathar's Guide to Everything.
How are character categories interpreted correctly? As a paladin, has he sworn an oath of Tempus and at the same time prays to Gond? Is that possible or is the explanation much easier?
In the rules there is no limit in this regard, the question arises in knowing especially how to interpret or focus correctly on the character.
Another dubious example of multiclass: Cleric of the domain of trickery (Loki) and Druid. If he were a cleric in the domain of nature and at the same time a druid, it would be easy to understand or at least assimilate, but the Loki / Druid mix did not fully understand how he focuses to play it correctly.
Another simple example taken from the player's manual: cleric of the domain of war and druid. What god does he pray? Or is it really supposed to pray to several and there is no problem in a polytheistic environment?
I have put several examples not because of the idea of needing an answer for each of them, but rather I looked for a generic answer for any mix that could be made with a multiclass character.