Looking at your screenshots, I want to be straight with you: what you’re trying to do is not currently possible with a single custom report in HubSpot’s native report builder.
Here is the specific limitation. HubSpot’s custom report builder lets you add multiple metrics to the Y-axis, but it requires a single X-axis dimension. When your two measures are separate date properties on the same object, there’s no way to normalize them to a “common delivery date” X-axis in one report because HubSpot treats each date property independently and can’t calculate a relative time offset between them.
The chart in the Knowledge Base article you referenced (multiple colored bars per time period) is achievable only when your measures share a natural common grouping dimension like deal amount broken by close date, or contacts by create date broken by source. It doesn’t work when your X-axis needs to be derived from two different date fields on the same records.
Your realistic options:
The simplest thing that works for most stakeholder dashboards is side by side. Create two separate reports, one per metric, both with date grouped by month on the X-axis. Place them next to each other on a single dashboard. Not the same as a combined chart visually, but it communicates the same insight and you can build it right now.
If there’s a logical relationship between your two date fields, you can create a calculated property that normalizes them to a single reference date and then report against that. This requires some property setup but it does make the combined chart technically possible.
If you genuinely need the exact visualization from the KB article with two date-based measures on a shared time axis, the cleanest path is exporting to Looker Studio, which has a free native HubSpot connector. It gives you the flexibility to define that kind of multi-date-field chart without the constraints of HubSpot’s report builder.
If you’re on Marketing Hub Enterprise, the Datasets feature is worth exploring for edge cases like this, though it may still hit the same structural wall on two separate date properties.
Bottom line: you’ve hit a real product limitation, not a setup error. If I were building this in production I’d go with the side-by-side dashboard option today and submit a Product Ideas post so HubSpot knows there’s demand for this.