To achieve this automation in Google Sheets, you can utilize Google Apps Script, which allows you to create custom functions and automate tasks within Google Workspace.

Here's a general outline of the steps to implement this automation:

1. Set Up Individual Spreadsheets:

   • Create individual spreadsheets for each "lender" if they don't exist already.

2. Central Database Spreadsheet:

   • Create a central database spreadsheet where the data will be initially input or collected.

3. Google Apps Script:

   • Write a script utilizing Google Apps Script.
   • Use triggers to run the script automatically based on certain events (e.g., on form submit, on edit, on time-driven trigger, etc.).

4. Data Transfer:

   • Write a function in the script to transfer the data the central database spreadsheet to the respective individual spreadsheets based on the "lender" information.

5. Data Security:

   • Set the appropriate sharing and access permissions for the central database spreadsheet to restrict access to authorized users only.

6. Testing and Deployment:

   • Test the script thoroughly to ensure it functions as expected.
   • Deploy the script to run as the appropriate user (e.g., the owner of the central database spreadsheet) and set the triggers as needed.

Here's a simplified example of what the script might look like:

function transferDataToIndividualSheets(e) {
  var centralSheet = SpreadsheetApp.getActiveSpreadsheet();
  var centralData = centralSheet.getDataRange().getValues();
  var centralHeaders = centralData[0];
  var lenderColumn = centralHeaders.indexOf('Lender'); // Assuming 'Lender' is the column header containing the lender information

  if (lenderColumn != -1) {
    for (var i = 1; i < centralData.length; i++) {
      var row = centralData[i];
      var lender = row[lenderColumn];
      if (lender != "") {
        var individualSheet = SpreadsheetApp.openById('individual_spreadsheet_id_for_' + lender); // Replace 'individual_spreadsheet_id_for_' with the actual naming convention
        var individualSheetData = individualSheet.getDataRange().getValues();
        // Assuming the first in individual sheets is used for tracking lenders        var targetRow = individualSheetData.findIndex(function (r) {
          return r[0] === lender;
        });
        (targetRow !== -1) {
          individualSheet.getRange(targetRow + 2, 1, 1, row.length).setValues([row]); // Assuming data starts from row 2 in individual sheets
        } else {
          individualSheet.appendRow([lender].concat(row));
        }
      }
    }
  }
}

Please note that this is a simplified example, and it's important to thoroughly test and adapt the to your specific use case to ensure it works reliably and securely. Additionally, ensure that the sharing and access permissions for the central database spreadsheet and individual spreadsheets are set appropriately to maintain data security.