Search all files based on first and in all listed files search the second patterns

Hello Linux Masters,

I am not a linux expert therefore i need help from linux gurus.
Well i have a requirement where i need to search all files based on first patterns and after seraching all files then serach second pattern in all files which i have extracted based on first pattern.
Forexample:

i have pattern1 ABC_DEF and pttern2 looks like GHI JKL

first i want all files which have ABC_DEF after seraching all files based on this pattern i want to serach second pattern GHI JKL in all serached files which i have listed based on pattern1.

Could you please help me out to solve this problem...?

Thanks in advance.

find . -type f -exec grep -l "ABC_DEF" + >>mylist.tmp
find . -type f -exec grep -l "GHI JKL" + >>mylist.tmp
sort mylist.tmp | uniq -d

---------- Post updated at 12:10 PM ---------- Previous update was at 11:48 AM ----------

find . -type f | xargs grep -l "ABC_DEF" | xargs grep -l "GHI JKL"