There are 3 ways to open a spreadsheet:
Project sidebar
Advanced issue search
App homepage
Project sidebar
Open a spreadsheet from the links on the project page (Project sidebar > Spreadsheets).
You can change your spreadsheet using the dropdown option in the project view.
If you want to add a new spreadsheet in your Project view, click Spreadsheets.
Issue navigator
Open a spreadsheet from the edit button on Jira Issue Navigator.
At the issue navigator screen, you can change the columns and reorder them.
App homepage
Click View Spreadsheets under the Spreadsheets menu.
Recent shows the spreadsheets which you opened recently.
System default filters are the standard system filters Jira provides initially. You are not able to change their query parameters. Please launch a spreadsheet from the issue navigator screen if you would like to use custom JQL or filter.