CodeQL library for Java/Kotlin
codeql/java-all 0.8.9 (changelog, source)

Member predicate MemberRefExpr::getReceiverExpr

Gets the expression whose member this member reference refers to, that is, the left side of the ::. For example, for the member reference this::toString the receiver expression is the this expression.

This predicate might not have a result in all cases where the receiver expression is a type access, for example MyClass::....

Expr getReceiverExpr()