Sounds like you have a filter action taking you to the second dashboard and filtering your treemap. Based on what you've written you want to keep the action filter for all of the second dashboard except the treemap. Create a new Highlight action for the treemap on the second dashboard.
Thanks Andrew Watson.
Your help brought me another step closer to getting where I want.
Now with the second dashboard showing tree map correctly with selected value (From tree map on first dashboard) highlighted, when I click on any other value on the tree map the originally selected value also stays selected no matter if I click on it again or any other value. This is because the previous dashboard still has that value selected and I'm not sure if we can change that when user has clicked on a different value in tree map on second dashboard. Even though the details on dashboard two are correctly filtering when I'm clicking on the tree map but tree map looks very confusing as it shows two values selected on it. Thanks again for looking into this and helping.
Actions can get confusing and sometimes, possibly as in your case, contradictory. Generally this can be overcome by altering the design - for example don't have duplicate treemaps on 2 dashboards, instead you could force usage of the first dashboard treemap to get to the detail in the second, remove the treemap in the second forcing the user back to the first dashboard. Possibly even move the 2 dashboards into 1 and have some downward scrolling from the user. Maybe add a 'back' button from the second dashboard to the first. There are multiple options all depending on the specifics of your circumstances.
I already did a work around where on the second dashboard I made the action filter visible to user with a note that if they want to view other options in tree map then just select 'all' on the filter to view other options before you could click those to see relevant details below. I think I may have to stick with that for now. I'll keep this question opened for now in case someone may have achieved the desired outcome as in my original post.