I wanted to perform migration of few of my users content to their respective OneDrive site. To do so, I used below PowerShell to identify URL of all users who already have a OneDrive sites and then used FileMigration wizard to import their content in the respective OneDrive Site. You can follow below steps to get the migration done. 

$TenantUrl = Read-Host "https://tenantname-admin.sharepoint.com/"
$LogFile = [Environment]::GetFolderPath("Desktop") + "\OneDriveSites.log"
Connect-SPOService -Url $TenantUrl
Get-SPOSite -IncludePersonalSite $true -Limit all -Filter "Url -like '-my.sharepoint.com/personal/'" | Select -ExpandProperty Url | Out-File $LogFile -Force
Write-Host "Done! File saved as $($LogFile)."
 Once you have the list of OneDrive path, go to SharePoint Admin center > Select Migration > File Share Migration > Download and install the migration agent.
Note : Note agent should be installed on a system which should have access to the files through network drive we want to migrate Use the user which you wish to use for migration and then provide the FileSharePath at the bottom of the screen. You can test if you have access to the UNC path using test button. Once everything is setup, you need can close this agent and let it run in the background. It will take sometime for the agent to appear in the SharePoint Admin center Agents screen


 Select Add task from Migration screen Select ‘Single source and destination’ and then select next Put the path of the users folder and select next Select OneDrive icon and select next Select the OneDrive path URL and then select the Document library you want the files to be migrated. Then select Next Prove the TaskName, Select the Active Agents and make sure you select Perform scan only and Preserve file share permissions as required. Select Next