Gmail allows you to map up to twelve recipient aliases to a single email address in what is known as a virtual user table that can store up to 2,000 entries. This allows you to distribute inbound email through your team in a very efficient way. 

To add a new mapping rule, hover over this section and click CONFIGURE:

Start by writing a short description for this routing and then select whether you wish to apply this mapping to All incoming messages or Only external incoming messages:

In the second part of the form, you define whether the message should also be sent to the original destination. If disabled, the message will only be received by addresses we are going to map on the next part:

In the third option, you can add individually the mappings you wish to apply by adding a list of addresses, separated by commas. 

First, write the destination address you need to map and then the address you want to map it to. For example, if you wish to map the same address to different destinations, you will have to add three lines, all starting with the same original address, but with a different destination in the second field:

The final option will add a copy of the original intended destination in the header: