I need a way to group or nest items within columns

I am trying to analyze a data set that has nested data. I have a column that contains projects, a column that contains activities of those projects, and dates that those activities were completed. I want a way to filter by projects, and then after that filter by the date of activity completion.

Here is an example of what I have (filtered by project):

Projects | Activities | Dates

Project #1 | Activity #3 | Date

Project #1 | Activity #1 | Date

Project #1 | Activity #2 | Date

Project #2 | Activity #2 | Date

Project #2 | Activity #3 | Date

Project #2 | Activity #1 | Date

Project #3 | Activity #3 | Date

Project #3 | Activity #2 | Date

Project #3 | Activity #1 | Date

Here is what I want to achieve (filter by project and activity):

Projects | Activities | Dates

Project #1 | Activity #1 | Date

Project #1 | Activity #2 | Date

Project #1 | Activity #3 | Date

Project #2 | Activity #1 | Date

Project #2 | Activity #2 | Date

Project #2 | Activity #3 | Date

Project #3 | Activity #1 | Date

Project #3 | Activity #2 | Date

Project #3 | Activity #3 | Date

I want to make a table that looks like this so I can design a column that shows the distance between the dates of the activities completed. I then want to use these distances to make a chart showing the average number of days between the activities. I feel as if I cannot do that without sorting with the method mentioned above. Can anyone point me in the right direction to accomplish what I am looking to do?