You can use %%~nf to get the filename only as described in the reference for for:
@echo off
for /R "C:\\Users\\Admin\\Ordner" %%f in (*.flv) do (
echo %%~nf
)
pause
The following options are available:
Variable with modifier Description
%~I Expands %I which removes any surrounding
quotation marks ("").
%~fI Expands %I to a fully qualified path name.
%~dI Expands %I to a drive letter only.
%~pI Expands %I to a path only.
%~nI Expands %I to a file name only.
%~xI Expands %I to a file extension only.
%~sI Expands path to contain short names only.
%~aI Expands %I to the file attributes of file.
%~tI Expands %I to the date and time of file.
%~zI Expands %I to the size of file.
%~$PATH:I Searches the directories listed in the PATH environment
variable and expands %I to the fully qualified name of
the first one found. If the environment variable name is
not defined or the file is not found by the search,
this modifier expands to the empty string.