public async Task<Either<Exception, List<Clientes>>> BuscarClientes()
{
    return await GetAllByAsync(x => true)
                    .BindAsync(clientes =>
        {
            clientes = clientes.Where(x => x.ativo == "S")
                               .OrderBy(x => x.Nome)
            return clientes
        }
}

public virtual async Task<Either<Exception, IEnumerable<TEntity>>> GetAllByAsync(Expression<Func<TEntity, bool>> funcao)
{
    try
    {
        return Right<Exception, Option<TEntity>>(await DBEntity.Where(funcao).ToListAsync());
    }
    catch
    {
        return ex;
    }
}