Pass node field data into Views block I'm bad with words, so hopefully I can get this across clearly. I'm using Views and the dRealty module. I've tried using relationships, and it's a no go.

I made a Views block of an "Agent" content type that has an agent_id (field_agent_id) text field. The dRealty module creates listings by pulling data from a RETS server, and the agent id (field_listing_agent_id) comes through as a text field. I need to show the data of the agent with the id that matches the listing on the node. How can I pass the field from the node into the Views block?

I'm using Views PHP to filter and I'm referencing How to Filter view by comparing 2 fields, but no luck.
The way I've typically seen that type of thing done is using Contextual filters (formerly called "Arguments" in Drupal 6). The Drupal 7 Advanced Views Tip: Contextual Filters screencast or this tutorial on Using Views Contextual Filters should provide a starting point for using them. In short, contextual filters are like regular filters, except that they allow arguments to be passed in dynamically rather than the filter criteria having to be statically set ahead of time.