Subsections are useful when you want to use just a subset of data from a Main Section. They will stay in sync, but allow you to use Rules and filters to pick which items to include in the subset.
How to Create a Subsection
In order to create a Subsection you must have first created a Main Section (also called simply "Sections"). You need to do this first, because a Subsection is only a subset of a Main Section and therefore cannot exist without it.
Once you have a Main Section, simply begin creating a new Section as you normally would. You will be presented with a number of options for creating the new Section, but the one you want to use is "Segment an Existing Section.". Click this box and more options will appear.
You'll need to first select which Section to segment. Use the drop-down to view all of your Sections and choose the appropriate one. Next, enter a name for the new subset. It may be helpful to you to include the name of the Main Section in the name of the new Subsection. For example, "Tables for Party - Kids" clearly indicates that the Main Section is "Tables for Party", while the Subsection contains just "Kids' Tables."
So now you have your Subsection created. But it's basically just a copy of the Main Section at this point. How do you turn the a Subsection into a subset of the Main Section? Easy, you use Rules.
First, navigate to the Places tab of the Subsection respectively. If you have just created the subset, you should be there already. You'll notice that a new button has appeared in the upper right-hand corner of the screen labeled "Rules." Click on this button to bring up a side menu.
On the Rules side menu, you can press the "New Rule Set" button to add a new group of Rules. Rules can be grouped together in rule sets so that you can create conditions for a Rule to be applied. By using a Rule Set, only people that meet all of the Rules in the Rule Set will be added to the Subsection.
Adding a specific Rule is easy. First select the Field you will use for the Rule. This can be any Field from the Section. Next select the criteria for the Rule. This can be that the Field "contains", "does not contain", "equals", etc. a specific value. You will enter this value in the "Value" field.
So, for example, the Rule "Type", "Equals", and "Kid" will filter for items in the Main Section where the "Type" Field is exactly equal to "Kid."
To delete any Rule, simply click the trash can icon next to the Rule. After you have created your Rules and Rule Sets, press "Apply Rules" at the bottom of the side menu to apply the Rules to the Subsection. You will immediately see the list update to display only the items that meet the criteria you have just created.
Subsections pull all of their data from the Main Section. Therefore, if you would like to add a new Field to a Subsection, you will need to add the field to the Main Section. It will then appear in all Subsections associated with that Main Section. Same for Groups.
However, you can edit Places data from within a Subsection. Any changes made to a Place will affect the Main Section and all associated Subsections. This is because an individual Place is treated as the same data point between the Main Section and all Subsections. This means you have to be careful! When you edit details for a Place within a Subsection, it may change data in many other Sections.