Let $L:\mathscr A \times \mathscr B \longrightarrow \mathscr C$ and $R\_1:\mathscr B^{op} \times \mathscr C \longrightarrow \mathscr A$ be two functors such that there is a bijection


$$ \mathscr C(L(A,B),C) \cong \mathscr A( A, R\_1(B,C)) $$ natural in $A,B,C$.


Is there any sufficient conditions to ensure existence of a functor
$ R\_2: \mathscr A^{op} \times \mathscr C \longrightarrow \mathscr B$ such that $(L,R\_1,R\_2)$ is an adjunction of two variables?


This mean that we would have bijections 


$$ \mathscr C(L(A,B),C) \cong \mathscr A( A, R\_1(B,C)) \cong \mathscr B( B, R\_2(A,C)) $$ natural in $A,B,C$.



Is there an analog of adjoint functor theorem for adjunctions of two variables?
Firstly, note that it is enough to construct an isomorphism $$\mathcal{C}(L(A,B),C) \simeq \mathcal{B}(B, R\_2(A,C))$$ The third natural isomorphism then follows automatically. Secondly, standard application of Yoneda's lemma shows that if for each $A\in \mathcal{A}$ you have a right adjoint $R\_2(A,\cdot)$ to $L(A,\cdot)$, then these right adjoints are natural in $A$ and assemble into a bifunctor $R\_2(A,C)$. There are various standard theorems that can be used to verify existence of right adjoint to each $L(A,\cdot)$, like Special Adjoint Functor Theorem or Freyd's AFT. The exact statement depends on your categories and functors. The simplest statement is Freyd's AFT: $\mathcal{B}$ must be cocomplete and locally small, $L(A,\cdot)$ must preserve all small colimits and satisfy solution set condition.


