ACTUALLY I´M DEVELOPING DASHBOARDS IN MY SPLUNK INSTANCE.
WE HAVE A SECOND INSTANCE WHERE RESIDES DASHBOARDS WHICH I WANT TO GET ACCESSFROM MY INSTANCE
As far as you have the other Splunk app name and dashboard URL you can either use <link> tag or HTML anchor tag <a>
Assuming you are in Splunk app named app1 and dashboard dash1 and want to navigate to Splunk app2 with dashboard dash2 you can try anchor HTML.
Through link tag in Simple XML
<link>app/app2/dash2</link>
Or with Anchor tag if you are using HTML panel within Simple XML
<a>app/app2/dash2</a>
You can use _target="blank"
within link or anchor to open the dashboard in a new window.
Refer to Splunk Documentation:
http://docs.splunk.com/Documentation/Splunk/latest/Viz/tokens#Define_tokens_for_conditional_operatio...
Go through this with mind set it is easy
https://docs.splunk.com/Documentation/Splunk/6.5.1/Indexer/Enablethesearchhead
YOu want to get access to dashboard OR the data residing in that instance. You can copy the dashboard xml (and any other dependencies like macros, fields extracts etc if exists) to your instance and create dashboard, add that second instance as your search peer and the dashboard should get populated.