Double flag varieties of Levi type with a finite number of orbits

We consider a double flag variety of the form $L\mathrm{/}Q\times G\mathrm{/}P$ where $G$ is a connected reductive group and $L$ is a Levi subgroup of $G$. The Levi subgroup $L$ acts diagonally on this double flag variety and a basic problem is to classify pairs of parabolic subgroups $P\subset G$ and $Q\subset L$ such that there are finitely many orbits for the considered action. We solve this problem in the case where $G$ is the general linear group by using representations of quivers.