对于您的请求，建议您使用SharePoint Online PowerShell命令.
对于SharePoint Online，您可以通过Get-SPOSiteGroup和Get-SPOUser命令查看用户和组的权限.
并在Get-SPOUser命令中选择要检查的用户.然后通过Export-csv命令将结果导出到文件中.
有关更多详细信息，请参阅下面的文章.
下面的文章是关于使用PowerShell进行清单清点:SharePoint Online

http://3sharp.com/blog/take-inventory-with-powershell-sharepoint-online /

谢谢
周卡尔

Hi,

For your request, I recommend you using SharePoint Online PowerShell command.
For SharePoint online, you could view the permission of the user and the group by Get-SPOSiteGroup and Get-SPOUser command. 
And select the user that you want to check in the Get-SPOUser command. Then export the results to file by Export-csv command. 
For more detailed information, you could refer to the article below.
The article below is about taking Inventory with PowerShell: SharePoint Online

http://3sharp.com/blog/taking-inventory-with-powershell-sharepoint-online/

Thanks,
Carl Zhou