I have a file (file1) which is like

host1
host2
host3
host4
the list goes on............


Now I want the above lines in files to be compared with files under
/opt/new/

File names are as below:
Dev
Prod
QA

And suppose host1 from file1 is found under Dev(file under /opt/new) than it should write under a seperate file New-list as host1-DEV

Thanks