The Solutions tab can be accessed by clicking on the button outlined in the image below. All Solutions in an Organization will be found here. There is also an option to search for a solution as well as create and import solutions.

Each Solution will have other concepts that were created in it such Flows, Buffers, Parameters, Connections, Relays etc. Click on a Solution's dropdown arrow as shown in the image below to expand and access these.

The search bar can be used to search for specific concepts as shown below.

Click on the button shown in the image below to create and import solution. Select either to create a new solution or import a solution.