Grouping a dataframe whilst making a pie chart

I have a data layer which consists of an attribute table of ~30 columns and ~6000 rows. This table contains information about buildings that are located close to parks in Amsterdam. I want to create a map in which I create for each park in Amsterdam a pie chart which shows the amount of buildings near that park. I know how to make the pie charts and how to display these on a map, the issue here is that I need to group the data to fall into parks. As of now, when I make the pie charts, the pie charts are made for EACH building (as I have 6000 buildings) and hence I need to group these buildings to each park. I have around 6000 observations for just 20 parks. So ideally I want to have 20 pie charts, one for each park.

I used a few tools (e.g. summary statistics) but these all give me back a table and hence I cannot make pie charts out of this anymore. I have attached three screenshots, 1 of the table, 2 of the output I got (and which I want to group to parks). I have also added a example of how I want my data to look like (note: the counties here substitute the parks in my data)