Check this out:
https://conf.splunk.com/session/2013/Using_Splunk_LisaGuinn_HowToUseDynamicDrilldown.pdf
Also this:
http://docs.splunk.com/Documentation/Splunk/6.4.2/Viz/Understandbasictableandchartdrilldownactions
It's going to look a bit like this:
MAIN DASHBOARD:
<dashboard>
<label>Dynamic Drilldown</label>
<row>
<panel>
<table>
<search>
<query>index=indexName ERROR | chart count by host </query>
<earliest>-7d@h</earliest>
<latest>now</latest>
</search>
<drilldown>
<link target="_blank">
/apps/MyApp/drilldown_target_dashboard_name?host=$row.host$
</link>
</drilldown>
<option name="drilldown">row</option>
</table>
</panel>
</row>
</dashboard>
DRILLED INTO DASHBOARD:
<dashboard>
<row>
<panel>
<chart>
<title>Host Application Error Details/title>
<search>
<query>
index=indexName host=$row.host$ | stats count by Application
</query>
<earliest>-30d@d</earliest>
<latest>now</latest>
</search>
</chart>
</panel>
</row>
</dashboard>
... View more