@Kimberleyieshaa There are many posts already related to the Find Children Activity, and it’s uses. One such post I have given below :
You can search for other posts related to your requirements, or you can explain actually what is the problem that you are facing if you’re trying to use it on an UI Element
Anil_G
ashokkarale
Ajay_Mishra
Gautham_Pattabiraman
BHUSHAN_NAGAONKAR1
vrdabberu
ABHIMANYU_THITE1
lrtetala
samantha_shah
shyamala_shyamu