Implications of a problem being in XP when parameterized by diameter Let $X$ be an NP-complete graph problem. Suppose $X$ is solvable in polynomial time on graphs of bounded diameter. In other words, $X$ parameterized by diameter is in XP. (Recall a problem is in XP if it can be solved in $n^{f(k)}$ time). Does this imply solvability in XP time for other interesting parameters?

If so, is there maybe even some more or less "standard" list or web of parameters and how they relate documented somewhere?
I think Figure 1 (page 4) of the paper "New Races in Parameterized Algorithmics" of Komusiewicz and Niedermeier is what you are looking for.

In particular, being in XP for the parameter diameter implies being in XP for parameters: min dominating set, max independent set, minimum clique cover, distance to cograph, distance to co-cluster, distance to clique, distance to cluster, vertex cover, and cluster editing.