  Croke-Kleiner admissible groups firstly introduced by Croke-Kleiner belong to
a particular class of graph of groups which generalize fundamental groups of
$3$--dimensional graph manifolds. In this paper, we show that if $G$ is a
Croke-Kleiner admissible group, acting geometrically on a CAT(0) space $X$,
then a finitely generated subgroup of $G$ has finite height if and only if it
is strongly quasi-convex. We also show that if $G \curvearrowright X$ is a flip
CKA action then $G$ is quasi-isometric embedded into a finite product of
quasi-trees. With further assumption on the vertex groups of the flip CKA
action $G \curvearrowright X$, we show that $G$ satisfies property (QT) that is
introduced by Bestvina-Bromberg-Fujiwara.
