Collapse all group except selected group in expandable listview android

Have the current expanded group position stored in a variable. In onGroupExpanded do the following.

private int lastExpandedPosition = -1;
private ExpandableListView lv; //your expandable listview
...

lv.setOnGroupExpandListener(new OnGroupExpandListener() {

    @Override
    public void onGroupExpand(int groupPosition) {
            if (lastExpandedPosition != -1
                    && groupPosition != lastExpandedPosition) {
                lv.collapseGroup(lastExpandedPosition);
            }
            lastExpandedPosition = groupPosition;
    }
});