Hello @Marco Dissel
Thanks for reaching out!
You can specify the collection of sites in your query string like this:
POST /search/query
{
"requests": [
{
"entityTypes": [
"driveItem"
],
"query": {
"queryString": "sample AND (Path:https://contoso.sharepoint.com/sites/sitename1 OR Path:https://contoso.sharepoint.com/sites/sitename2 OR
Path:https://contoso.sharepoint.com/sites/sitename3
)"
}
}
]
}
Refer this similar post and documentation.
You can only fetch managed properties in Graph API response. If you are looking to fetch any custom field which is not predefined crawled property, you need to add it to search schema, manage-search-schema.
Hope this helps.
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