A Study to (1) Compare How BI 456906 is Taken up in the Body of Healthy People and People With Liver Problems and (2) Find Out How People With Overweight and Obesity, With and Without Liver Problems, Tolerate Different Doses of BI 456906

Inclusion Criteria -Part A: * Male or female subjects with age ≥18 years (or the minimum country specific age of consent if \>18 years) and 75 years, inclusive at the screening visit. * Body mass index (BMI) of 18.5-40.0 kg/m2 (inclusive). * Signed and dated written informed consent in accordance with International Council on Harmonisation-Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial. * Women of childbearing potential must be willing and able to use two forms of effective contraception where at least one form is highly effective method of birth control per ICH M3 (R2) that results in a low failure rate (i.e. \<1% per year when used consistently and correctly). A list of contraception methods meeting these criteria is provided in the subject information. Please note that oral contraceptives are not allowed during the treatment period. A woman is considered of childbearing potential, i.e. fertile, following menarche and until becoming post-menopausal unless permanently sterile. Permanent sterilisation methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy. Tubal ligation is NOT a method of permanent sterilisation. A postmenopausal state is defined as no menses for 12 months without an alternative medical cause. Further inclusion criteria apply. -Part B: * Male or female subjects between the ages of ≥18 (or the minimum country specific age of consent if \>18 years) and 75 years, inclusive, at the screening visit. * Subjects with overweight or obesity, defined as BMI ≥27 kg/m2 at the screening visit. * A minimum absolute body weight of 70 kg for females and 80 kg for males at the screening visit. * Signed and dated written informed consent in accordance with ICH-GCP and local legislation prior to admission to the trial. Further inclusion criteria apply. Exclusion criteria -Part A: * Estimated Glomerular Filtration Rate (eGFR) \<60 mL/min/1.73 m2 (Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula). * Personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2, manifest hypo- or hyperthyroidism at screening. * Calcitonin ≥20 pg/mL (5.84 pmol/L) at the screening visit. * History of chronic or acute pancreatitis or elevation of serum lipase/amylase \>2×ULN, or fasting serum triglyceride levels of \>500 mg/dL (\>5.65 mmol/L) at screening. Further exclusion criteria apply. -Part B: * Prior surgery of the gastrointestinal tract that could interfere with body weight (including minimally invasive/endoscopic bariatric devices, bariatric surgery including metabolic operation that involves resection and/or reconstruction of any portion of the gastrointestinal tract) except appendectomy and simple hernia repair before randomization. However, a subject previously treated with reversible weight loss devices such as gastric banding, or intragastric balloon and removed longer than 12 months before screening should not be excluded. * Glycosylated Hemoglobin, Type A1 (HbA1c) ≥11% at screening or diagnosed with type 1 diabetes mellitus. * Exposure to Glucagon-like-peptide 1 (GLP-1) receptor agonist-based therapies (within 3 months prior to screening or within 5 half-lives of the drug, whichever is longer). * Personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2, manifest hypo- or hyperthyroidism at screening. Further exclusion criteria apply.