Try something like this instead:

Add-PSSnapin SqlServerCmdletSnapin100 -ErrorAction SilentlyContinue

Add-PSSnapin SqlServerProviderSnapin100 -ErrorAction SilentlyContinue

$searchTerm = "something"

# note the second entry is for a default instance so you would only change the word "server" and leave the "\default"

$databases = @{"server\instance"="db_name";"server\default"="db_name"}

foreach($database in $databases.Keys)

{

Set-Location ("SQLSERVER:\SQL\" + $database + "\Databases\" + $databases.Get_Item($database) + "\FileGroups")

foreach($FileGroup in Get-ChildItem){

foreach($File in $FileGroup.Files){

# in here you can build up any string you like using the logical file name and physical

# path, or whatever else, and push it into an XML file

"FileGroup=" + $FileGroup.DisplayName + ". FileName=" + $File.FileName + ". FileID=" + $File.ID

}

}

}