Issue when use dropdown filter, bex query takes long time

Hello friends,

I have the following issue, i have a dropdown which have the following event on select:

DS_1.setFilterExt("0PLANT", DROPDOWN_1.getSelectedValue());

DS_4.setFilterExt("0PLANT", DROPDOWN_1.getSelectedValue());

DS_2.setFilterExt("0PLANT", DROPDOWN_1.getSelectedValue());

DS_3.setFilterExt("0PLANT", DROPDOWN_1.getSelectedValue());

DROPDOWN_10.setItems(DS_1.getMemberList("ZCMP_UGV", MemberPresentation.EXTERNAL_KEY, MemberDisplay.TEXT, 500,"UGV"));

DROPDOWN_2.setItems(DS_2.getMemberList("ZCMP_UGV", MemberPresentation.EXTERNAL_KEY, MemberDisplay.TEXT, 500,"UGV"));

DROPDOWN_3.setItems(DS_2.getMemberList("ZCMP_UGV", MemberPresentation.EXTERNAL_KEY, MemberDisplay.TEXT, 500,"UGV"));

when i select some value on dropdown, it takes long time, this problem its fixed when i delete the last three lines, which set items from others. dropdowns.

Can anyone help me?