  We consider correlation functions in 6d $(2,0)$ theories of two
$\frac{1}{2}$-BPS operators inserted away from a $\frac{1}{2}$-BPS surface
defect. In the large central charge limit the leading connected contribution
corresponds to sums of tree-level Witten diagram in AdS$_7\times$S$^4$ in the
presence of an AdS$_3$ defect. We show that these correlators can be uniquely
determined by imposing only superconformal symmetry and consistency conditions,
eschewing the details of the complicated effective Lagrangian. We explicitly
compute all such two-point functions. The result exhibits remarkable hidden
simplicity.
