Visualization links are in the dataset's expanded box. Assigning the "database" (genome build) with pencil icon -> Edit attributes will link-in the external apps, which are incorporated into Galaxy, that have a browser for that build. Overview here: https://wiki.galaxyproject.org/Learn#Visualization
Visualization link at the top of the masthead will also allow visualization for data aligned to built-in genomes and custom builds. Here is how to do set up a custom build from a custom genome for vis and certain other functions: https://wiki.galaxyproject.org/Learn/CustomGenomes#Custom_Builds
The Galaxy 101 tutorials have visualization components, for a simplified demonstration examples, with context: http://usegalaxy.org/galaxy101. More 101 content is at the very top of this wiki: https://wiki.galaxyproject.org/Support
Let us know if you need more help. I was not quite sure how you wanted to move from visualization data to additional mapping. Explaining your goals will help us to guide with a strategy.
Best, Jen, Galaxy team