Basic query is available as GUI:

where you can use objects: “Site Url”, “Site Name” and “Refinable String 0″..”Refinable String 99”. Conditions would be “is equal to”, “is not equal to”, “starts with” and “not starts with”. Or you can select “Advanced query builder” and enter KQL query.

Advanced query builder

Advanced query builder allows us to use more site properties then “Site Url”, “Site Name” and “Refinable Strings” and more conditions than “is (not) equal to” and “(not) starts with”.

E.g. we can use “Title”, “Created”, “Modified” site properties and “=”,”:”,”<“, “>”, “<=”, “>=” conditions.

Working queries examples:

created>=2022-07-21
modified>1/31/2023
created>12/31/2021 AND modified>=7/31/2022
created<=2020-11-15 OR modified>2023-02-06 (?)
created<=2020-1-15 OR modified>2023-01-31 (?)
created<=11/15/2020 OR modified>1/31/2023
title:test
SiteTitle:test
RefinableString09:Test*
RefinableString09<>Test
RefinableString09=Birding AND RefinableString08<>Included

Not working queries examples:

site:https://contoso.sharepoint.com/sites/test* 
RefinableString11 = Birds # (do not use spaces in advanced query)
Path:https://contoso-my.sharepoint.com
Template:STS
Template:"SITEPAGEPUBLISHING#0"
Template:SITEPAGEPUBLISHING*
? RefinableString09<>Birding AND RefinableString08:Official
modified>31/1/2023 (should be like modified>2023-01-31
)

Query against custom site property (aka property bag value)

You can create custom site property and assign value to the property with
Set-PnPAdaptiveScopeProperty or Set-PnPPropertyBagValue.
Property must be with “Indexed” parameter. Once the property is set up, m365 search crawls site and creates crawled property. Then you map crawled property to some pre-created refinable string managed property. You can assign alias to this managed property.

In my test scenario I used RefinableString09 with alias SiteCustomSubject.

Site property value	Query	result
Birding	RefinableString09:Bird	does not work
Birding	SiteCustomSubject:Bird	does not work
Birding	RefinableString09:Bird*	works
Birding	SiteCustomSubject:Bird*	does not work
Birding	RefinableString09:Birding	works
Birding	SiteCustomSubject:Birding	does not work
Birding	RefinableString09:Birding*	works
Birding	RefinableString09=Birding	works
Birding	RefinableString09=Bird	does not work
Birding	RefinableString09=Bird*	does not work
Birding	SiteCustomSubject=Birding	does not work
	RefinableString09<>Birding	works
	RefinableString09=Birding AND RefinableString08<>Included	works

Query against multi-value property.

Site property value	Query	result
TestA TestB	RefinableString09:TestA	works
TestA TestB	RefinableString09 = ‘TestA TestB’	does not work
TestA TestB	??? RefinableString09=’Test10 Test5′	does not work
TestA TestB	RefinableString09:TestB	?
TestA,TestB	RefinableString09:Test*	works
TestA,TestB	RefinableString09=Test*	does not work
TestA,TestB	RefinableString09:Test	does not work
TestA,TestB TestA;TestB TestB TestA TestA TestB	RefinableString09:TestB	works
TestA, TestB TestB,TestA TestA TestB	RefinableString09=TestA	does not work
TestA,TestB	(basic) RefinableString09 starts with test	works

Some more findings

Modify adaptive scope

If you need to modify adaptive scope – you’d better delete it and create a new one. The reason – if you want to validate what sites are included in scope with GUI – via button “Scope details” – you want to see only sites that are in scope, but that’s not the case when you modify the scope, because if you modify the scope – you’d see sites that are not in scope with “Removed” status.

Alternatively you can use filter to filter out removed from scope sites.

what else?

What is the takeaway from this for SharePoint administrators? We would be asked to configure SharePoint the way compliance…

References

Adaptive scopes Retention Policies Data Lifecycle Purview