Short answer: yes. For example, you can operate one Web Dispatcher in the DMZ and another one in the Intranet. If both Web Dispatchers are reachable under the same URL from all browsers, then everything is simple.
The tricky part comes if these Web Dispatchers are reachable under different URLs, especially if you have multiple backend systems with different hostnames behind these Web Dispatchers. The problem is that the application (like Fiori launchpad) knows only one single URL to generate for starting an application. Therefore, this URL has to be reachable for all browsers, regardless from where they access the system.
For a single system that does not generate URLs to other systems there is usually not problem with URL generation, because follow-up URLs in HTML or other responses are either relative to the current hostname or generated based on incoming hostname. However, if URLs are generated ahead of time into documents like WSDL files, then you can chose one one access point for a single resource.
For more info, see
- URL Generation in an AS-ABAP - Web Dispatcher Configuration (https://help.sap.com/saphelp_nw75/helpdata/en/48/6a82a684f4350ce10000000a42189d/content.htm)
- SAP Business Client URL construction (https://help.sap.com/saphelp_nw75/helpdata/en/4c/5bde0697817511e10000000a42189b/content.htm)
- Using Proxies (https://wiki.scn.sap.com/wiki/display/BSP/Using+Proxies)