These instructions apply to OnePager v6.0 or later. If you are running OnePager v5.3 or earlier, please read this article instead.
OnePager is capable of using any Microsoft Project/Excel field for any purpose (e.g. swimlanes, conditional formatting, task labeling, etc.) However, only a select number of fields are imported by default from Microsoft Project/Excel into OnePager when you create your new project view. This is done for performance reasons, as importing several hundred Project/Excel fields all at once would seriously degrade OnePager's performance.
If you are attempting to use a Project/Excel field for a particular purpose, but do not see it available in the Project-View Properties form, this means that the custom field was not specified in your initial template when you first created the project view.
There are two ways to expand your list of available fields.
Reports with only one Snapshot
If you only have one snapshot in your project view, your field dropdowns will have a dashed line in the middle:
To include a field that wasn't imported originally, scroll down to the bottom of your list of available fields until you get to the dashed line. Fields above this line have already been imported. Fields below the line exist in Project or Excel, but have not yet been imported. Once imported, the new field will appear above the dashed line for future use so that you don't have to retrieve it each time.
Reports with more than one Snapshot
For data integrity and performance reasons, unlimited field mappings are limited to project views that contain a single snapshot. This means that if you have a project view with multiple weekly or monthly snapshots, you will not be able to retroactively map a new custom field until you first reduce your project view to a single snapshot. To do this, go to View > List All. This will give you a list of all of your available snapshots. Highlight a snapshot and hit the Delete key on your keyboard until only one snapshot remains:
Once you have reduced your project view to only one snapshot, the dashed line will automatically appear in all of your dropdowns, indicating freedom to map new auxiliary fields. Once you have adjusted your field mappings, you are welcome to begin adding new snapshots again.