Sorry it took so long for anyone to respond, Mike.
My thought is that you could then include the URL field somehow (as a separate view, text only, set transparency of the color to 0% so the view looks "blank") on Dashboard A where you have established an action that takes you to Dashboard B.
You would then just need to also make the selection on Dashboard A filter the URL field. Assuming they use the same data source, you will then have "set" the URL and moved to Dashboard B with the one click on Dashboard A. I have not tested this, so I'm interested to find out if this works for you.
The action to move you from the origin dashboard to the second dashboard has to be separate from the action that brings up a URL within a Webpage Object within the second dashboard. The passing of the URL is dashboard specific, so you cannot specify a destination for the URL -- if a Webpage object is on the current dashboard the URL is opened there, otherwise your default browser is opened with the URL passed to it.
Consider your first action on the origin dashboard that links you to table or chart within your second dashboard. On the second dashboard, create a URL filter action on the table or chart you move into. Set this action so it runs when you hover over it. This way once start to move the mouse within the second dashboard (assuming the table or chart does not have much white space) the URL is passed immediately to the Webpage object when your mouse hits a bar or text within the table or chart.
Hope this helps,