You can find the most detailed available information about 1 on 1s held by navigating to Insights > Managers > Reports > 1 on 1 Details.

Filter the data by any time frame you'd like to see in the top right of the report. Then download the data into a spreadsheet to see all the details of those 1 on 1 meetings in the bottom right corner. Results are automatically filtered to show 1 on 1s by you, or those downstream from you in your organization (such as direct reports and skip level reports).

Here is an example of what you would see when clicking View next to one of the meetings: