Hi @jENNYg112 ,
I did a test again.
Please check this test.
My USERS List:

My SALES List:

The Result:

My Flow:

item()?['IDUser']
item()?['Name']

item()?['IDS']
item()?['Sale']
body('Select_2')
body('Select')
item()?['IDUser']
tems('Apply_to_each')?['IDS'] item()?['Name']

body('Filter_array')
{
"Name":@{replace(replace(replace(variables('String'),'"',''),'[',''),']','')},
"Sale":@{items('Apply_to_each')?['Sale']}
}

item()?['Name']
union(body('Select_4'),body('Select_4'))

outputs('Compose')
item()?['Name']
items('Apply_to_each_2')
{
"Name":@{items('Apply_to_each_2')},
"Sale":@{body('Join')}
}
Best Regards,
Sunshine Gu
If I solve your problem, please mark my reply as a solution so that I can help more people in the future.