When viewing resources' utilization in the Resource LWC, this feature allows you to see utilization for tasks grouped by project. This allows you to see the total allocated effort per resource, then by project, then by task.
To open the project in a new tab, click on the Open Project icon to the left of each project.
You can choose to see utilization per day, per week or per month using the zoom option in the top right corner. When you switch between days, weeks, and months, the total allocated displayed per resource, per project, per task will automatically adjust.
If you choose to view allocation in % using the % icon in the top right corner, then utilization is displayed in percentages per resource, per project, per task.