Thanks.
There's plenty of scope for tuning here, few of the indexes are fully supportive.
You have a residual predicate
[SurveillanceDashboardRepository].[dbd].[fResult].[GeoLevel] as [a].[GeoLevel]=(2)
on a 27 million row table. An "actual" execution plan with runtime figures would show how painful that filter is. Can you post one? You could always run the results into a #temp table then drop it afterwards.
Are you at liberty to create / amend indexes?
For fast, accurate and documented assistance in answering your questions, please read this article.
Understanding and using APPLY, (I) and (II) Paul White
Hidden RBAR: Triangular Joins / The "Numbers" or "Tally" Table: What it is and how it replaces a loop Jeff Moden