Consider the setting of categories enriched over a suitable monoidal category V$\mathbb V$.
We define Dist(X,Y):=V−Cat(Xop⊗Y,V).$$\mathrm{Dist}(X,Y):=\mathbb V−\mathrm{Cat}(X^ \mathrm{op}⊗Y,\mathbb V).$$
Recall the definition of ends. Taking the end is an operation of signature
Dist(X,X)→V.$$\mathrm{Dist}(X,X)→\mathbb V.$$
QUESTION: Is there an analogue for functors into V of higher arity. More explicitly: Is there a canonical operation of signature
V−Cat(X?⊗X?⊗X?,V)→V$$\mathbb V−\mathrm{Cat}(X^?⊗X^?⊗X^?,V)→\mathbb V$$
where the ? are to be replaced by either op or nothing.
MOTIVATION: I like to think of the composition ⊗$\otimes$ of (2-ary)distributors and the right adjoints to D⊗−$D\otimes−$ and −⊗E$−\otimes E$ as "horn-filling" (in the sense of viewing categories as simplicial sets).
I hope to find a similar situation for "3-ary distributors" - Whenever there is a (oriented?) tetrahedron of 3-ary functors with one side missing we should be able to find the missing side.
So given
U∈Dist3(X,Y,A)$$U\in\mathrm{Dist}^3(X,Y,A)$$ V∈Dist3(Y,Z,A)$$V\in\mathrm{Dist}^3(Y,Z,A)$$ W∈Dist3(Z,X,A)$$W\in\mathrm{Dist}^3(Z,X,A)$$
there should be ?(U,V,W)∈Dist3(X,Y,Z)$$?(U,V,W)\in\mathrm{Dist}^3(X,Y,Z)$$
and related adjoints.
Of course Dist3$\mathrm{Dist}^3$ remains to be defined.