Developer a OEM plugin or a Dashboard

hi,

I spent the last 2 weeks reading about how to create a OEM plugin and a custom dynamic dashboard for OEM, but i didn't find docs that help me.

I read http://docs.oracle.com/cd/E24628_01/doc.121/e25159/plugin_lifecycle.htm#EMPRG121 and http://docs.oracle.com/cd/E11857_01/em.111/e12135/mgmt_plugin.htm about oem plugin and https://docs.oracle.com/middleware/1213/bam/bam-user-guide/GUID-DAED8857-565E-4204-9A63-8E89AB841656.htm#BAMUG101 about Oracle BAM.

We developed a page in which we have all databases aggregate in the same place (I attached print screen) because i know that OEM has the same data, but in different pages (one for each DB).