Thread watchedQuestion Many IFS in dependent drop down list.

I have tried in put these ifs in the data validation to make dependent drop down list, however, it only works with 2 statements. After that it doesn't show what I want. And I want to make a lot of ifs.
=IFS(รายการสั่งเหล็ก!B2="ฉาก",OFFSET(Sheet1!$E$1,1,0,COUNTA(OFFSET(Sheet1!$E$1,1,0,30))),รายการสั่งเหล็ก!B2="รางน้ำ",OFFSET(Sheet1!$H$1,1,0,COUNTA(OFFSET(Sheet1!$H$1,1,0,30))),รายการสั่งเหล็ก!B2="รางพับ",OFFSET(Sheet1!$KE$1,1,0,COUNTA(OFFSET(Sheet1!$K$1,1,0,30))))
The table I would like to make is to be able to just click click each size of the steel I wanna order, and each type of steel has it own sizing method.