$OU=@("OU Path 1",
        "OU Path 2",
        "OU Path 3")

$OU | ForEach ($user in (Get-ADUser -SearchBase $_ -filter {(lastlogondate -notlike "*" -OR lastlogondate -le $90days) -AND (passwordlastset -le $90days) -AND (enabled -eq $True)} -Properties lastlogondate, passwordlastset | Select-Object name, lastlogondate, passwordlastset, samaccountname))
{

....