Can we create a data source through a file or local variables?

I want to seperate data form main code and use them in seperate file similar to local.tf or variables.tf, however even in the docs there is no reference.

use case

I am trying to create access logging for s3 bucket. Target bucket is not managed by s3 so I want to make sure that it exists before using it via data source

resource "aws_s3_bucket" "artifact" {
  bucket   = "jatin-123"
}

data "aws_s3_bucket" "selected" {
  bucket = "bucket.test.com"
}
resource "aws_s3_bucket_logging" "artifacts_server_access_logs" {
  for_each = local.env
  bucket   = data.aws_s3_bucket.selected.id

  target_bucket = local.s3_artifact_access_logs_bucket_name
  target_prefix = "${aws_s3_bucket.artifact[each.key].id}/"
}

Yes, you can have data sources in whatever file you want.
Terraform basically does not care about the file composition and their names and just lumps all .tf files in the same directory into one big blob.

The docs state:

A module is a collection of .tf [...] files kept together in a directory.
Terraform evaluates all of the configuration files in a module, effectively treating the entire module as a single document.
Separating various blocks into different files is purely for the convenience of readers and maintainers, and has no effect on the module's behavior.