TechNet has an article to create and view Search Scope, but I followed all the procedure still can’t get Item in the search scope.
After hours search, I found you will need to create a content source in your Fast Search Query service as well.
Below is the PowerShell I run to create the search scope
a list of all available content sources$searchapp = Get-SPEnterpriseSearchServiceApplication "FASTQuery Service Application"
Get-SPEnterpriseSearchCrawlContentSource -SearchApplication $searchapp$searchapp = Get-SPEnterpriseSearchServiceApplication "FASTQuery Service Application"
$scope = New-SPEnterpriseSearchQueryScope -Name "productsscope " -Description "product scope created in PowerShell" -SearchApplication $searchapp -DisplayInAdminUI $trueNew-SPEnterpriseSearchQueryScopeRule -RuleType PropertyQuery -ManagedProperty ContentSource -PropertyValue "Product Master"-FilterBehavior Include -url http://simsearch.simapps -scope $scope -SearchApplication $searchapp